Harvesting and ensilage cutting apparatus

ABSTRACT

Harvesting and ensilage cutting apparatus, comprising a chopper rotor in a housing with a front inlet opening, a pair of cooperating feed rolls mounted for counterrotation about substantially vertical axes closely in advance of said front inlet opening, stalk cutting means below said pair of feed rolls and a pair of forwardly extending guide means for guiding row crop toward said pair of feed rolls.

United States Patent 1191 Zweegers Feb. 13, 1973 [54] HARVESTING ANDENSILAGE References Cited CUTTING APPARATUS UNITED STATES PATENTS [761Invent: Paws Zweegers, 2,657,513 4/1953 Martin ..56/13.4 drop,Nleuwenduk, 46, Netherlands 3,090,188 5/1963 06:11am. ..56 503 1,779,02010/1930 Swim ..56/503 [22] 1971 3,455,094 7/1969 0611mm 256/503 [21]App]. No.: 201,296

Primary ExaminerRussell R. Kinsey Foreign pp Priority DataAttorney-Watson, Cole, Grindle & Watson Nov. 23, 1970 Netherlands..70l708l [57] ABSTRACT March 3, 1971 Netherlands 1.7102855 Harvestingand ensilage cutting apparatus comprising Sept. 7, 1971 Netherlands ..7112316 a chopper rotor in a housmg with a front mlet opening, a pair ofcooperating feed rolls mounted for coun- 52 US. (:1 ..56/l3.4, 56/503terrotatio" about Substantially vertical axes Closely in 51 Int. Cl...A0ld 55/26, AOld 49/00 advance of Said from inlet Opening, Stalkcutting [58] Field of Search ..56/500, 501, 502, 503, 13.9, means belowsaid P of feed rolls and a P of 5 4 wardly extending guide means forguiding row crop iii. ll

toward said pair of feed-rolls.

26 Claims, 17 Drawing Figures PAIENTEDFEB 13 I975 3.7 1 5, 873 SHEET 1or 9 k! f III PAIENTEDFEB 1 3 1915 3,715,873 SHEET 3 [1F 9 i0 5 26 s O I2e 7 o 29 I l 20 o 9 I a; l 30 10 PATENTED FEB 1 3 I973 SHEET 0F 9PATENTED FEB 1 3 ma SHEET 5 BF 9 PATENTEU FEB 1 3 I975 SHEET 7 OF 9HARVESTING AND ENSILAGE CUTTING APPARATUS My invention relates to aharvesting and ensilage cutting apparatus for row crops such as corn.

Known apparatus for harvesting row crops such as corn and simultaneouslycutting the crop into small pieces are complicated and comprise a largenumber of rotary and/or reciprocatory elements.

It is an object of the invention to provide a simple, reliably operatingapparatus for the above purpose. This object is attained according tothe invention by providing a harvesting and ensilage cutting apparatuscomprising a chopper rotor in a housing with a front inlet opening, apair of cooperating feed rolls mounted for counter-rotation aboutsubstantially vertical axes closely in advance of said front inletopening, stalk cutting means below said pair of feed rolls and a pair offorwardly extending guide means for guiding row crop to said pair offeed rolls.

Said apparatus is of simple construction and ensures a correct feed ofthe cut stalks into the chopper. For the stalks, after having beensevered, are immediately grasped by the pair of feed rolls, which feedit positively into the chopper at a constant accurately determinedspeed.

According to a further feature of the invention, the stalk cutting meanscomprise a series of knives distributed around the lower edges of thepair of feed rolls and cooperating in a shear cut with a counterknife.Although it is conceivable that the knives of one feed roll serve ascounter knife for the knives of the other feed roll, it is preferred tomount a separate stationary counter knife transversely under the pair offeed rolls, whereas the knives of the pair of feed rolls intermeshwithout touching each other, such that the counter knife cooperatesalternately with knives of the two feed rolls. Preferably the cuttingedge of the stationary counter knife is situated substantially. in theplane which contains the axes of the two feed rolls. Thus, the stalksare reliable severed in the nip between the two feed rolls so that theycan be grasped immediately by the two rolls to be fed into the inletopening of the chopper.

In known apparatus, bulky and complicated guide means are mounted nearthe feed means for obtaining a reliable guidance through the feed meansof the sometimes very long and topheavy plants with tend to fall on theearth after their stalks have been severed. However, it is preferredaccording to the invention to have the periphery of the pair of feedrolls disengaged at their front and outer side parts and to shield onlythe outer parts of the cutting circles of the knives at the lower edgesof the feed rolls. This shielding may be obtained by a pair of guidemeans which extend forward from the housing of the chopper and may beformed as a pair of flat arms extending along the lower edges of thepair of feed rolls. Even when the top of a cut plant lands on the earthsideways behind the feed rolls, its stalk is reliably grasped by thedisengaged outer parts of the feed rolls and thus reliably fed into theinlet opening of the chopper.

The front part of the pair of forwardly directed guide arms may carrylateral projections which face each other and form supports for the cutplants and preferably almost touch each other in the center line betweenthe pair of guide arms. These projections may be resilient or may bemovably mounted so that they can yield when the pair of guide arms ismoved along both sides of a row of standing plants.

A reliable feed by the pair of feed rolls may be ensured by providingsaid rolls with substantially longitudinally extending ribs distributedover the circumference of the rolls. These ribs may be inwardly movablewith respect to the roll on which they are mounted and may for instancebe spring biased to their outermost position.

Preferably a short duct having a substantially rectangular closedsection connects the circumference of the pair of feed rolls with theinlet opening of the chopper housing. The rear edge of one of theupstanding sides of said duct may serve as counter knife for the knivesof the chopper rotor, whereas the front edges of the sides of said ductmay serve as scraper means for the feed rolls. If desired, the counterknife extending along one of the sides of said duct may be formed by aseparate, quickly replaceable element which may be so mounted that it isaccessible from the outside.

The knives of the rotating chopper rotor press the fed-in stalks againstone of the sides of the connecting duct, the length of which between thefront edge adjacent the associated feed roll and the rear edge servingas counter knife need not be more than a few centimeters. This enhancesan even size of the small pieces obtained, because the stalks will besteadily fed towards the chopper knives.

SUMMARY OF THE DRAWINGS FIG. 1 is a perspective view of a machineaccording to the invention, mounted at the right side of an agriculturaltractor,

FIG. 2 is a view from above the machine of FIG. 1,

FIG. 3 is a side view of the machine according to FIG. 1,

FIG. 4 is a view of the machine according to FIG. 1 in vertical section,

FIG. 5 shows the stalk cutting means in detail,

FIG. 6 is a view from above of part of the machine according to FIG. 1,partly in section, with another embodiment of the guide arms,

FIG. 7 is a view from above of the guide arms according to FIG. 6,

FIGS. 8 and 9 are a side view and transverse section respectively of aguide arm according to FIGS. 6 and 7,

FIGS. 10 and 11 are views from above of other embodiments of the pair ofguide arms,

FIG. 12 is a horizontal section of another embodiment of the pair offeed rolls,

FIG. 13 is a front view of the chopper housing with another embodimentof its counterknife,

FIG. 14 is a cross section of the parts shown in FIG. 13,

FIG. 15 is a horizontal section at enlarged scale of a detail of thecounterknife mounting according to FIG. 14,

FIGS. 16 and 17 show other shapes of acounterknife suitable for beingused in an embodiment according to FIG. 13.

DESCRIPTION OF PREFERREDEMBODIMENTS The combined harvesting and ensilagecutting apparatus according to the invention is mounted on one end of ahollow transverse beam 1, extending sideways from a tractor and havingat its other end coupling means for the three-point linkage system ofthe tractor 2. A belt drive 3 is mounted at the rear side of thetransverse beam 1 for transmitting the drive from the power take-offshaft of the tractor 2, to the horizontal main shaft 4 of the machine.The main shaft 4 is journalled in a bushing attached to the beam 1, andfixed to its rear end it carries a pulley for the belt drive 3 and achopper rotor 5 adjacent said pulley. The rotor 5 is enclosed in ahousing 6. The rotor 5 comprises a disc 7 of sheet metal attached to abushing 8, which is fixed on the shaft 4. The disc 7 carries a pluralityof regularly distributed, radially directed angle irons 9, each of whichcarries a chopper knife 10 of L-section, the forward edge of which issharpened to form a radially directed cutting edge. The cutting edges ofthe knives 10 cooperate with the rear edge of a stationary knife 11fixed against the side wall of a rectangular channel 12 opening into thelower part of the housing 6. When looking on the front surface of thedisc 7, it rotates counterclockwise, whereas the knife 11 is fixedagainst the right side wall of the channel 12. When plants are fed intothe channel 12, they are chopped into little pieces between thestationary knife 11 and the knives 10 of the rotor 5 which rotates athigh speed.

The angle irons 9 and the knives 10 of the rotor 5 are so shaped thatthey also operate as an impeller for blowing the air and the finelydivided pieces of the plants from the inlet opening 12 to a dischargestack 13 mounted on top of the housing 6. The discharge stack 13 isconnected to a flexible tube 14, for instance a ribbed thermoplastictube, which may be so directed that it discharges into a wagon ridingalongside the machine.

A bevel gear 15 is mounted on the front end of the main shaft 4 andcooperates with a bevel gear 16 mounted on a vertical auxiliary shaft 17rotatably mounted in a frame part 18 directed forwardly from the mainbeam 1. A plain gear 19 is mounted on the lower end of the auxiliaryshaft 17. The upper ends of two vertical shafts 20 and 21 are fixed tothe underside of the frame part 18 and the lower ends of the shafts 20and 21 are fixed in bushings 22 mounted at the forward end of horizontalsupport 23, the rear end of which is fixed to the housing 6. Feed rolls24 and 25 are rotatably mounted on the shafts 20 and 21, and plain gears26 and 27 are fixed to the upper end of the feed rolls. The gear 19 onthe auxiliary shaft 17 meshes with the gear 27 (FIG. 2) and the gear 27meshes with the gear 26, so that the main shaft 4 when rotated cause asynchronous counterrotation of the two feed rolls 24,

'25 via the auxiliary shaft 17.

Each feed roll 24 or 25 comprises a cylinder 28 of smaller diameter thanthe gear 26 or 27, and a flange 31 mounted to the lower end of thecylinder. Each cylinder 28 carries eight flat ribs 29 which extendbetween the gear 26 or 27 and the flange 31 and are inclined outwardlyand rearwardly with respect to a radius. The ribs 29 extend over thefull height of the cylinder 28 and an upwardly inclined strip 30 ismounted in the corner between the front of each rib 29 and the flange31, see FIG. 1.

A cutting disc 32 provided with cutting teeth 33 is mounted under theflange 31 of each feed roll 24 and 25. Each cutting disc 32 comprisessix equal contigous segments 34, see FIG. 5. The dimensions of thecutting discs 32 and their teeth 33 are so chosen that the teeth 33 ofthe two feed rolls 24, 25 intermesh without touching each other. In thenip between the two feed rolls, the two cutting discs 32 rotaterearwardly. The cutting edges of the teeth 33 are radially directed andthe rear edges of the teeth are inclined. A stationary knife 35 (FIG. 6)fixed to the front edge of the support 23 between the two bushings 22rests against the underside of the two cutting discs 22. The front edgeof the stationary knife 35 cooperates in a shearing action with theradial cutting edges of the teeth 33.

As shown in FIG. 6, the pair of feed rolls 24 and 25 are mounted inadvance of the inlet opening 12 of the chopper rotor 5 with their nipsomewhat displaced to the left with respect to the main shaft 4, whereasthe inlet opening 12 is displaced somewhat farther to the left. Thestationary knife 11 fixed against the right side wall of the inletopening 12 extends with its front edge up to the outer edge of the ribs29 of the roll 25 so as to serve as a doctor means for plant partsclinging to the ribs 29. The stationary knife 11 is fixed to an angleiron 36 which is itself fixed to the front wall of the housing 6.Another angle iron 37 is fixed along the left side of the inlet opening12 and serves as a doctor means for the ribs 29 of the roll 24. Theupper wall of the inlet channel is formed by a plate 38 which is anextension of the upper edge of the inlet opening 12 and extends betweenthe gears 26 and 27 so as to substantially close the top of the inletchannel. A plate 39 is in a similar way provided between the lower edgeof the inlet opening 12 and the outer edge of the flanges 31 of therolls 24 and 25. Thus, a short, closed inlet channel for the plantsextends'between the rolls 24 and 25 and the inlet opening 12.

FIGS. 1 to 4 show an embodiment of the guide means comprising a pair ofguide arms 40 and 41 extending forwardly from the housing 6 along thelower edge of the outer sides of the pair of feed rolls 24 and 25. Theguide arms 40 and 41 have a length of almost 6 feet and end in arelatively sharp tip. At their inward sides, they carry inwardly andrearwardly inclined resilient tines 43, which extend almost to thecenter line between the two arms and almost touch each other. Guideplates 44, 45 with a rearwardly inclined front edge are mounted betweenthe guide arms 40 and 41 respectively and the front part of thecircumference of the rolls 24, 25, so that their rear edges are spacedwith a small clearance from the lower flange 31 of said rolls 24, 25.The connection between the guide arms 40, 41 and the front wall of thehousing 6 may be reinforced by triangular braces 46, 47, but it isimportant that these reinforcing braces 46, 47 have a small height sothat the greater part of the height of the rolls 24, 25 is disengaged atthe laterally outward part of their circumference.

A hood 48 is mounted on the frame part 18 and the top of the hood 48carries supports for adjustable connection of the stem 50 of a forwardlydirected fork shaped element 49.

The apparatus operates as follows:

The tractor 2 is driven along a standing row of stalks such as corn, insuch a way thatthe row of plants passes between the resiliently yieldingtines 43 of the guide arms 40 and 41. Stalks which do not grow exactlyin the center line, contact the guide plates 44, 45 and are forcedtoward the center line, whereas the mounting of the machine itself hasalso a limited flexibility in a direction transversely to said centerline so that the stalks are fed exactly into the nip between the pair offeed rolls 24, 25. Simultaneously, the fork 49 and the front wall of thehood 48 push the stalk to a forwardly inclined position. A few inchesabove the ground, the stalk is engaged by the teeth 33 of the cuttingdiscs 32 of the pair of feed rolls 24, 25 and these teeth push the stalkagainst the stationary knife 35, where the stalk is cut in a shearingaction. While the plant falls, its lower end is immediately grasped bythe ribs 29 of the pair of feed rolls 24, 25. While the stalk of theplant is fed into the inlet opening 12 of the chopper rotor 5 by thepair of feed rolls 24, 25, the greater part of the plant falls on thetines 43 of the pair of guide arms 40, 41. It is not detrimental if partof the plant falls on the ground beside the guide arms, since it willengage the outer part of the circumference of the feed rolls 24, 25 anda plant which has fallen aside will thus reliably be grasped by the ribsof the rolls and drawn inwardly toward the chopper rotor. It isimportant that the ribs 29 of the two rolls 24, 25 are mutually offset(see FIGS. 2 and 6) to obtain a good feeding action toward the inletopening 12. The plant is fed through the channel connecting the rolls25, 24 with the inlet opening 12 and is chopped to little pieces by theknives 10 of the chopper rotor 5 and the stationary knife 11 against theside wall of the channel. The plant parts extending between the nip ofthe rolls 24, 25 and the inlet opening 12 move over the stationary knife11 which acts as a scraper for stripping the plant parts from the roll25 and also acts as a guide for guiding the plant parts to the rearcutting edge of the knife. The speed ratio between the rolls 24 and 25and the rotor 5 can be so chosen that the plants are cut into very finepieces, and because of the small distance between the pair of feed rollsand the chopper rotor, the plant parts are securely held so that it isavoided that large pieces can fall into the chopper housing. The mass ofpieces is blown out of the chopper housing into a discharge stack 14 andis delivered into a waggon travelling alongside the machine.

The hood 48 preferably extends to a position over and in advance of thepair of feed rolls 24, 25, so that it holds the uncut stalks in asuitable inclined position in front of the nip of the pair of rolls 24,25. This is important for reliably grasping the cut stalks since thefork 49 engages only the top part of the plants which can bend while thestalk remains upright.

Inside the hood 48, a known per se sharpening device may be mounted forsharpening the knives 10 of the chopper rotor. After sharpening, theclearance between the knives l0 and the stationary knife 11 can beadjusted by moving the chopper rotor 5 over the main shaft 4 towards thestationary knife 11 and tightening it again.

While the chopper rotor has a horizontal shaft in the describedembodiment, it is also possible to use a chopper rotor with a verticalshaft. This has the advantage that the channel between the pair of feedrolls 24, 25 and the inlet opening 12 can be shorter, since thecylindrical forward part of the chopper rotor can be positioned closelyadjacent the cylindrical rear parts of the rolls 2 4, 25. The speed ofrotation of the pair of feed rolls 24, 25 is preferably 100 to a fewhundred revolutions per minute, whereas the speed of rotation of thechopper rotor 5 is preferably appreciably higher.

In the embodiment according to FIGS. 1 to 4, the guide arms 40 and 41have a closed circular section and the tines 43 are mounted on theirperiphery. In this embodiment, the tines have to carry a heavy load.FIGS. 6 to 9 show an embodiment, of the guide arms, in which the load onthe tines is lower. In this embodiment, the guide arms 51, 52 have achannel section, the open sides of which face each other, and in thechannels are mounted the coiled ends 53 of tines 54 of a type generallyused for haymakers. As in the first embodiment, the tines are inwardlyand rearwardly inclined and almost touch each other in the center linebetween the two guide arms 51, 52. The upper flange 55 of the channelsection of the arms 51, 52 is extended toward the center line andreplaces the guide plates 44, 45 of the first embodiment. The upperflange 55 protects a large part of the rearwardly inclined tines 54,whereas the tines are supported on a rod 57 fixed under the upper flange55 and extending in longitudinal direction of the arms 51, 52. Thechannel section arms 51, 52 end forwardly in a relatively sharp pointedtip 56, the inner edges of the upper flanges 55 diverging toward thetops of the arms. Thus, the guide arms reliably catch the plants betweenthem. The slot between the pair of flanges 55 narrows rearwardly so thatthese flanges guide the plants reliably toward the nip between the pairof feed rolls. At their rear ends, the upper flanges 55 closely followthe circumference of the lower ends of the pair of feed rolls 24, 25.Past the feed rolls 24, 25, the upper flanges 55 widen again so as toprotect the cutting teeth 32 of the feed rolls 24, 25 and to obtain astrong connection with the housing 6.

In the embodiments of FIGS. 10 and 11, the tines of the guide arms aremovable by the plants which move toward the pair of feed rolls. Thus,the repeated flexing movement of the tines of the first describedembodiments become unnecessary and danger of breakage of the tines isavoided.

In the embodiments of FIGS. 10 and 11 the pair of guide arms 61, 62 havethe same general shape as the guide arms 51, 52 in the embodiment ofFIGS. 6 9. A bar 63, 64, extends from the pointed tip of the arms 61, 62respectively along and spaced from the inner edge of the upper flange ofsaid arm 61, 62 and terminates short of the pair of feed rolls 65, 66.

In the embodiment according to FIG. 10, each bar 63, 64 carries fourvertical shafts 67, 68, 69, and a hub 71 is mounted for free rotation oneach of said shafts. Each hub 71 carriers a plurality of radial tines,e.g. six, which are regularly distributed about the circumference of thehub. The tines 72 end just short of the center line 80 of the guidemeans so that they do not touch each other when rotated by the cornstalks passing between the pair of guide arms 61, 62.

In the embodiment according to FIG. 11 each bar 63 and 64 carries twovertical shafts 74 and 73 and a freely rotatable pulley or sprocket 75is mounted on each of said shafts. An endless belt or chain 76 istrained around the two pulleys or sprockets 75 of each guide arm 61 and62 and said belt or chain 76 carries a series of outwardly protrudingtines 77. The tines 77 of the two belts or chains 76 end just short ofthe center line 80 of the guide arm arrangement so that the tines do nottouch each other when moved by the uncut row of stalks passing betweenthe guide arms 61 and 62.

In the described embodiments, the feed rolls 24, consisted of a rigidcylinder carrying a plurality of rigid ribs 29. Since the dimensions ofthe stalks and ears passing between the pair of feed rolls varyconsiderably, it may be advantageous to build the feed rolls and/or ribsof a yielding material such as rubber. In FIG. 12 another possibility isshown for obtaining a regular feed with varying dimensions of thethickness of the mass passing between the pair of feed rolls.

According to FIG. 12, the ribs 81 are retractable in radial directioninto the cylinder 82 of the feed rolls. This has the advantage that boththick and thin stalks are held securely between the pair of feed rollsand are thus regularly fed into the chopper housing so that a regularchopping is obtained.

Each feed roll comprises a hollow cylinder 82 having a plurality oflongitudinal-slots 83 regularly distributed over its circumference. Inthe shown embodiment each cylinder has three slots. A rib 81 havingsubstantially a V-section closes said slot 83 in that one edge of theribs is formed into a hinge eye 84 pivotably mounted on a pin 85fastened along the inner edge of one side of the slot. Viewed in thedirection of rotation of the feed rolls (indicated by arrows), the pivotpins 85 ere fastened along the rear edges of the slots 83. The frontedge (viewed in the direction of rotation) of each rib 81 is resilientlyloaded in radial outward direction by a pressure spring'86 mounted inthe hollow interior of the feed roll between said front edge and aL-shaped support 87, the extremity of which is fixed to the inner wallof the cylinder 82.

The front leg 88 of the V-section of the ribs 81 is curved with a radiushaving its center in the axis of the pivot pin 85, so that said frontleg 88 closely follows the front edge of the slot 83, when the rib 81 ispushed inwardly by the plants grasped between the pair of feed rolls.Thus, no plant parts can penetrate into the hollow interior of the feedroll. Also, the front edge of the rib engaging the plants always has thesame angular position with respect to the circumferential wall of thecylinder 82, so that a varying thickness of the mass grasped between thepair of rolls does not influence the manner of feeding caused by theribs. Said angular position of the front leg 88 with respect to thecylinder wall is rearwardly directed with respect to the direction ofrotation and is so chosen as to obtain a regular feed of the crop intothe chopper rotor. By the construction described this direction ismaintained for any position of adjustment of the ribs caused by avarying thickness of the mass of crop held between the feed rolls.

FIGS. 13 17 show an embodiment with a quickly replaceable counter knifefor cooperation with the chopper knives. As stated, the knives of thechopper rotor itself can quickly be resharpened by a known per sesharpening device mounted on the machine, for inv stance within the hood48, so that it can be moved to a position in which it engages therotating knives of the chopper rotor. However, the stationary counterknife mounted in the inlet opening of the chopper housing is not readilyaccessible in the earlier described embodiments and thus, it may bepreferable to provide a quickly replaceable easily accessible counterknife as described below.

In FIG. 13, the chopper housing 91 is indicated in phantom lines. Therectangular inlet opening 92 is positioned below the shaft of thechopper. The counter knife 93 is located along the left side of theinlet opening 92. In this embodiment the counter knife 93 is made ofhard steel strip and, as shown in FIG. 15, clamped between the side wall94 of the inlet opening 92 and a clamping piece 95 mounted in aninterior recess of the side wall 94. The clamping piece 95 comprises anelongated rectangular block fitting in a corresponding slot extendingover the height of the side wall 94, the counter knife 93 being bent toZ-shape and the flange of said counter knife being clamped between theslot and the clamping piece. FIGS. 16 and 17 show counter knives 93A,93B of a different shape, for instance with an inclined flange, andadapted shapes of the clamping pieces 95A, 95B.

The side wall 94 of the inlet opening 92 comprises a series of throughholes, through which extend screws 96 welded to the clamping piece 95.Nuts 97 are screwed on the outwardly extending ends of the screws 96 andclamp the clamping piece against the counter knife and in the slot ofthe side wall. The nuts 97 are elongated so as to be readily accessiblefrom the exteri- The lower end part of the counter knife 93 or 93A or938 extends downwardly through a slot 98 of corresponding shape providedin the lower wall of the inlet opening 92. After loosening the nuts 97,the counter knife 93 or 93A or 938 can be removed by pulling itdownwardly through the slot 98. In the embodiment shown the counterknife 93 or 93A or 93B has a symmetrical shape and it has cutting edgesalong two parallel longitudinal side edges, so that after removing thecounter knife, it can be rotated over 180 and reinserted so that thesecond longitudinal edge can be used as cutting edge. After both cuttingedges are worn, the knife may be disposed off.

FIG. 14 shows the knives 99 of the chopper rotor which cooperate withthe counter knife 93, and also the vanes 100 mounted to the oppositeface of the disc shaped rotor so as to serve as a fan.

What I claim is:

1. Harvesting and ensilage cutting apparatus comprising a chopper rotorin a housing with a front inlet opening, a pair of cooperating feedrolls mounted for counter-rotation about substantially vertical axesclosely in advance of said front inlet opening, stalk cutting meansbelow said pair of feed rolls and a pair of forwardly extending guidemeans for guiding row crop toward said pair of feed rolls in which saidstalk cutting means comprise a counter knife and an annular series ofknives mounted against the lower end of each of the two feed rolls forcooperation of each of said knives with said counter knife in a shearingaction.

2. Apparatus according to claim 1, in which said knives cooperate withthe counter knife which is stationary and mounted transversely under thepair of feed rolls, the knives of the two rolls intermeshing withouttouching each other, such that the counter knife cooperates inalternation with knives of the two feed rolls.

3. Apparatus according to claim 2, in which the cutting edge of thecounter knife is disposed substantially in the plane containing the axisof the pair of feed rolls.

4. Apparatus according to claim 1, in which a short duct forms asubstantially closed passage between the periphery of the pair of feedrolls and the inlet opening of the chopper housing.

5. Apparatus according to claim 4, in which a separate, quicklyreplaceable counter knife is mounted along the rear edge of one of theside walls of said duct.

6. Apparatus according to claim 5, in which said last mentioned counterknife extends through a slot in the lower wall of said duct.

7. Apparatus according to claim 5, in which a clamping piece holds saidlast mentioned counter knife in a longitudinal slot of the associatedside wall of the inlet duct.

8. Apparatus according to claim 5, in which the last mentioned counterknife comprises a hardened steel strip and is bent along at least onelongitudinal line.

9. Apparatus according to claim 8, in which the cross section of thelast mentioned counter knife is symmetrical such that two parallellongitudinal side edges can alternately be used as a cutting edge.

10. Apparatus according to claim 9, in which the operative part of thelast mentioned counter knife extends along the side wall of the inletduct and the remaining part of the counter knife is enclosed between theclamping piece and the slot in the side wall of the inlet duct.

11. Apparatus according to claim 4, in which the rear edge of one of theupstanding side walls of said duct serves as a counter knife for thechopper rotor knives.

12. Apparatus according to claim 1, in which the outlet of the chopperrotor is connected to a flexible ribbed thermoplastic discharge tube.

13. Apparatus according to claim 3, in which the outer portions of thecutting circle of the knives at the lower edges of the feed rolls areshielded by said pair of guide means which extend forwardly from behindthe feed rolls along the outer edges of the feed rolls.

14. Apparatus according to claim 1, in which said guide means includeguide arms of channel section, the upper flange of each channel sectionguide arm having an inner edge which is curved at its rearward end, saidcurved end being slightly spaced from the associated feed roll forshielding the knives at the lower edge of each feed roll.

15. Apparatus according to claim 1, in which said resiliently secured tosaid guide arms.

16. Apparatus according to claim 1, in which said guide means includeguide arms, movable extensions mounted on said guide arms adapted to bemoved rearwardly by the stalks passing between said pair of guide arms.

17. Apparatus according to claim 16, wherein a plurality of verticalshafts are mounted on each said guide arm, and outwardly extending tinesbeing mounted for free rotation on each said shaft.

18. Apparatus according to claim I, in which a plurality oflongitudinally extending ribs are mounted along the circumference ofeach of the pair of feed rolls.

19. Apparatus according to claim 18 wherein a peripheral flange ismounted at the lower end of each feed roll, and a forwardly inclinedstrip is mounted in the corner between the front surface of each saidrib and said flange at the lower end of each feed roll.

20. Apparatus according to. claim 18, in which said ribs are mounted tothe periphery of each feed roll so as to be displaceable in asubstantially radial direction.

21. Apparatus according to claim 20, in which the cross section of eachsaid rib is V-shaped with their open ends facing inwardly.

22. Apparatus according to claim 20, in which the ribs are outwardlyspring biased.

23. Apparatus according to claim 20, in which the rear edge of each rib,viewed in the direction of rotation of the associated feed roll, ispivotably connected with said roll.

24. Apparatus according to claim 20, in which the periphery of each feedroll is provided with a series of longitudinally extending slots inwhich the radially displaceable ribs are so mounted that they close theassociated slot in any assumed position of the rib with respect to theroll.

25. Apparatus according to claim 24, in which the front leg of theV-shaped cross section of each rib, viewed in the direction of rotation,is bent with a radius of curvature, the center of which substantiallycoincides with the pivot axis of the rib.

26. Apparatus according to claim 22, in which the ribs' are springbiased by torsion springs extending in a longitudinal direction of theribs.

1. Harvesting and ensilage cutting apparatus comprising a chopper rotorin a housing with a front inlet opening, a pair of cooperating feedrolls mounted for counter-rotation about substantially vertical axesclosely in advance of said front inlet opening, stalk cutting meansbelow said pair of feed rolls and a pair of forwardly extending guidemeans for guiding row crop toward said pair of feed rolls in which saidstalk cutting means comprise a counter knife and an annular series ofknives mounted against the lower end of each of the two feed rolls forcooperation of each of said knives with said counter knife in a shearingaction.
 1. Harvesting and ensilage cutting apparatus comprising achopper rotor in a housing with a front inlet opening, a pair ofcooperating feed rolls mounted for counter-rotation about substantiallyvertical axes closely in advance of said front inlet opening, stalkcutting means below said pair of feed rolls and a pair of forwardlyextending guide means for guiding row crop toward said pair of feedrolls in which said stalk cutting means comprise a counter knife and anannular series of knives mounted against the lower end of each of thetwo feed rolls for cooperation of each of said knives with said counterknife in a shearing action.
 2. Apparatus according to claim 1, in whichsaid knives cooperate with the counter knife which is stationary andmounted transversely under the pair of feed rolls, the knives of the tworolls intermeshing without touching each other, such that the counterknife cooperates in alternation with knives of the two feed rolls. 3.Apparatus according to claim 2, in which the cutting edge of the counterknife is disposed substantially in the plane containing the axis of thepair of feed rolLs.
 4. Apparatus according to claim 1, in which a shortduct forms a substantially closed passage between the periphery of thepair of feed rolls and the inlet opening of the chopper housing. 5.Apparatus according to claim 4, in which a separate, quickly replaceablecounter knife is mounted along the rear edge of one of the side walls ofsaid duct.
 6. Apparatus according to claim 5, in which said lastmentioned counter knife extends through a slot in the lower wall of saidduct.
 7. Apparatus according to claim 5, in which a clamping piece holdssaid last mentioned counter knife in a longitudinal slot of theassociated side wall of the inlet duct.
 8. Apparatus according to claim5, in which the last mentioned counter knife comprises a hardened steelstrip and is bent along at least one longitudinal line.
 9. Apparatusaccording to claim 8, in which the cross section of the last mentionedcounter knife is symmetrical such that two parallel longitudinal sideedges can alternately be used as a cutting edge.
 10. Apparatus accordingto claim 9, in which the operative part of the last mentioned counterknife extends along the side wall of the inlet duct and the remainingpart of the counter knife is enclosed between the clamping piece and theslot in the side wall of the inlet duct.
 11. Apparatus according toclaim 4, in which the rear edge of one of the upstanding side walls ofsaid duct serves as a counter knife for the chopper rotor knives. 12.Apparatus according to claim 1, in which the outlet of the chopper rotoris connected to a flexible ribbed thermoplastic discharge tube. 13.Apparatus according to claim 3, in which the outer portions of thecutting circle of the knives at the lower edges of the feed rolls areshielded by said pair of guide means which extend forwardly from behindthe feed rolls along the outer edges of the feed rolls.
 14. Apparatusaccording to claim 1, in which said guide means include guide arms ofchannel section, the upper flange of each channel section guide armhaving an inner edge which is curved at its rearward end, said curvedend being slightly spaced from the associated feed roll for shieldingthe knives at the lower edge of each feed roll.
 15. Apparatus accordingto claim 1, in which said guide means include guide arms, rearwardly andinwardly inclined tines being mounted at one end on said guide arms, thefree ends of the tines on the respective guide arms being spaced fromone another at the centerline between said guide arms, and the tinesbeing resiliently secured to said guide arms.
 16. Apparatus according toclaim 1, in which said guide means include guide arms, movableextensions mounted on said guide arms adapted to be moved rearwardly bythe stalks passing between said pair of guide arms.
 17. Apparatusaccording to claim 16, wherein a plurality of vertical shafts aremounted on each said guide arm, and outwardly extending tines beingmounted for free rotation on each said shaft.
 18. Apparatus according toclaim 1, in which a plurality of longitudinally extending ribs aremounted along the circumference of each of the pair of feed rolls. 19.Apparatus according to claim 18 wherein a peripheral flange is mountedat the lower end of each feed roll, and a forwardly inclined strip ismounted in the corner between the front surface of each said rib andsaid flange at the lower end of each feed roll.
 20. Apparatus accordingto claim 18, in which said ribs are mounted to the periphery of eachfeed roll so as to be displaceable in a substantially radial direction.21. Apparatus according to claim 20, in which the cross section of eachsaid rib is V-shaped with their open ends facing inwardly.
 22. Apparatusaccording to claim 20, in which the ribs are outwardly spring biased.23. Apparatus according to claim 20, in which the rear edge of each rib,viewed in the direction of rotation of the associated feed roll, ispivotably connected with said roll.
 24. Apparatus acCording to claim 20,in which the periphery of each feed roll is provided with a series oflongitudinally extending slots in which the radially displaceable ribsare so mounted that they close the associated slot in any assumedposition of the rib with respect to the roll.
 25. Apparatus according toclaim 24, in which the front leg of the V-shaped cross section of eachrib, viewed in the direction of rotation, is bent with a radius ofcurvature, the center of which substantially coincides with the pivotaxis of the rib.